Partition Migration

Both range and query partitions can be migrated between different types of storage. For example, you have the range partitions created in Range Partitions and, after a few months, the volumes of documents grow to 5 and there is no longer enough space on the fast SSD device to hold all of them. Instead, the oldest and least queried volumes (Vol1-Vol3) are migrated to a local disk drive, which represents a slower storage tier:

After years of data growth, the volumes of documents grow to 50. After migrating between storage tiers, the partitions are eventually distributed among the storage tiers:

Multiple databases, even those that serve on different storage tiers, can be grouped into a super-database in order to allow a single query to be done across multiple tiers of data. Databases that belong to a super-database are referred to as sub-databases. A single sub-database can belong to multiple super-databases:

For details on super-databases and sub-databases, see Tiered Storage.